In JewelSmith, you have the ability to display, in an ArtCAM model, either the front (which is the top of the ring) or the back relief (which is the inside of the ring). These two when combined make a new assembly model. This new assembly model is machined using the multi-sided wizard. The default mode for JewelSmith is to have no back relief when generating a basic ring or flat 3D shape.
The front and back relief is not exclusively for rings, it is a feature of JewelSmith and can be used on flat pieces as well. Both the front and back relief can be made using ArtCAM techniques or be loaded in from an existing relief. An assembly model is made from removing the back relief from the front relief (tick Use Back Relief), as the diagram shows.
The back relief can also be negative, to produce a court-ring.
The front relief is the master, from which the back relief is removed; this means that as long as the back relief covers the front relief the area will be removed, as this flat piece diagram shows.